dt-bindings: at24: add microchip, 24lc[0-9]+ to the compatible pattern

dt-bindings: at24: add microchip, 24lc[0-9]+ to the compatible pattern

arch/arm/boot/dts/uniphier-ref-daughter.dtsi has

  compatible = "microchip,24lc128", "atmel,24c128";

and 'make ARCH=arm dtbs_check' warns this:

  eeprom@50: compatible: ['microchip,24lc128', 'atmel,24c128'] is not valid under any of the given schemas (Possible causes of the failure)

Microchip 24LC128 is the device used on this board, and I see it in
https://www.microchip.com/wwwproducts/en/24LC128

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>